When Christians celebrate sacraments and rituals they draw on patterns of human celebration and invest them with new significance in the light of reflections upon the God who is revealed in Jesus Christ. So baptism, for example, was invented neither by the early church nor by Jesus of Nazareth. Found in many religious and social traditions, it may signify incorporation into a given community, affirm identity or ritual cleansing.

Believers, following biblical injunctions and developing their liturgical traditions, have transformed such actions to give corporate and personal expression to their religious belief. The manner of worship expresses patterns of belief: lex orandi, lex credendi. For people of faith these become imbued with a sacramental reality so that they become "outward signs of inward grace," effecting what they signify, doing this in memory of the wonders God has done with humanity in its liberation.

Marriage is a variable and culturally conditioned social institution with no inherent religious inspiration, but subsequently clothed with meaning by various faiths. In many cultures it was rooted more in property contracts or ways of social engineering through annexing others into extended family networks.

As in so many other aspects, Jesus of Nazareth turns prevailing attitudes and social institutions upside down. When it comes to marriage, his vision and that of the early Church communities, is a long way from promoting patriarchal ownership of women as property, masculine power over perceived feminine passivity, or the aim of increasing economic or social prestige through the coming together of small families as powerful forces.

The Catholic church, in both its eastern and western traditions, possesses a rich historical treasury of rituals celebrating diverse forms of human belonging. Religious communities, through communally expressed vows, enable men and women in same-sex communities to express a solidarity of human relationships. Although rare today, this also happened in medieval times in mixed-gender religious communities. Catholic historians such as the late John Boswell and Alan Bray have unearthed the blessing of same-sex couples, both in sworn-brotherhood rituals, as well as in other forms more closely approaching heterosexual betrothal and marriage rites.

What is fundamental to a Catholic understanding of marriage as a sacrament, a significant religious action, is the centrality of the personal relationship. Social recognition or status is dependent upon and subsequent to a deep interpersonal commitment. The couple themselves are the ministers of the sacrament, not a member of the clergy. The latter's declaratory function is as a formal witness of the faith community in such celebrations.

The potential for sacramentality in heterosexual relationships is largely taken for granted in Christian traditions, even if not universally counted as a sacrament. Growing numbers of Catholic theologians as well as those involved in marriage preparation and relationship-support, affirm the potential of same-sex relationships for being good and holy.

The question then is not whether same-sex relationships can be morally justified and graced, but when, under what conditions, or according to what criteria they can be so.

What is required of religious institutions is that the debate about same-sex unions should shift from the rhetoric of taboo, to a discourse about an inclusive framework of Christian sexual ethics: do no unjust harm; free consent; mutuality; equality; commitment; fruitfulness; and social justice. It should move from a fixation upon the sacrament of marriage to the promotion of the sacramentality of human relationships. In so doing, it will recognise that just as their may be a non-physiological fruitfulness in mixed gender couples unable to conceive children, same-sex unions can be equally fruitful.

Abrahamic religions are, generally speaking, far from initiating this level of dialogue. They, (including many lesbian, gay, bisexual and transgendered adherents) are mostly stuck at the stage of still arguing ideological positions. Many of us, people of faith or not, do not wish to be encumbered with, or use, either patriarchal vocabulary or the property-rights baggage of marriage as commonly understood. Nevertheless many of us strongly affirm the sacramentality of our human relationships as entirely consistent with the fundamentals of our respective religious traditions.

Catholics believe that the church is actualised by sacraments of unity. No gift of love to anyone is just "for the two of us". The sealing of every shared covenant and the life that is shaped are significant and needed ways in which the church finds God present in human relationships.

One of the many "best kept secrets" of the Catholic church is its development of doctrine and practice. It has creatively celebrated various comings together in human relationships in its past. It is not beyond its wit to do the same today for this and coming generations, but do its hierarchies have the will?